Glossary of property, roof and climate risk terms

Matrikkelen is Norway's official register of land, properties and buildings, kept by Kartverket. For each building it records facts such as build year (byggeår), usable floor area (BRA), number of floors and building type; for each property it records the cadastral numbers and boundaries. HOMAI reads these values from the register and uses them as they are. The AI never overrides them.

A cadastral unit (matrikkelenhet) is a registered property in the Matrikkel. It is identified by the municipality number, the farm number (gårdsnummer, gnr) and the title number (bruksnummer, bnr), sometimes followed by a leasehold or section number. A HOMAI report shows the gnr/bnr of the analysed address together with the plot (teig) boundary from the register.

The construction year recorded for a building in Kartverket's Matrikkel. HOMAI treats byggeår as an official value and never re-estimates it. It drives the Age factor, the heaviest of the 10 roof risk factors with a default weight of 0.25. Byggeår dates the building, not the roof, so it says nothing about a roof that was replaced later.

HOMAI does not measure roof age. It uses the building's official byggeår as a stand-in for the age of the roof. If the roof has been replaced since the building went up, the proxy makes the roof look older than it is. The historical-change factor looks for visible change between older and newer orthophotos, but it does not date the roof, and images are never used to estimate age.

BRA (bruksareal) is a building's usable floor area, measured inside the enclosing walls. It is one of the main area measures in Norwegian building and property records. HOMAI takes BRA from the Matrikkel and shows it with the report's registry data. The vision model is not allowed to estimate area from images, so a building without a registered BRA shows the value as not assessed.

SEFRAK is a national register of older buildings, mainly those from before 1900. The dataset owner is Riksantikvaren, the Directorate for Cultural Heritage. HOMAI checks the address against the SEFRAK data through Geonorge and adds a heritage flag to the property when there is a match. The flag is information for the reader; it is not one of the scoring factors.

A zoning plan (reguleringsplan) is a detailed land-use plan adopted by the municipality. It sets what an area may be used for and how it may be built on. HOMAI reads the planning zones that apply to an address from the plan services on Geonorge and shows the plan's fields exactly as published, without interpreting what they allow.

A consideration zone (hensynssone) is an area in a municipal plan where special rules apply, for example for safety, infrastructure or cultural heritage. A hazard zone (faresone) is the kind of consideration zone used for danger, such as flood or landslide. HOMAI lists the faresoner and hensynssoner registered for an address alongside NVE's own hazard maps.

An orthophoto is an aerial or satellite image corrected so that its scale is the same everywhere, which lets it be used like a map. In Norway, current and historical orthophotos are published through Norge i bilder. HOMAI uses them among the up to seven images its vision model sees. Their age depends on when the area was last photographed, so they are not live images.

LiDAR measures distances with laser pulses sent from an aircraft and builds a dense 3D point cloud of the ground and everything on it. Kartverket's national height model, published on Høydedata, is built from such data. HOMAI uses it for terrain, building height, slope and aspect, gives the vision model a shaded-relief image of it, and cross-checks roof pitch against it.

A digital terrain model (DTM) describes the bare ground. A digital surface model (DSM, in Norwegian DOM) also includes buildings and vegetation. The difference between the two is the height of what stands on the ground. HOMAI calculates building height as DOM minus DTM from Kartverket's national height model, together with ground elevation, slope and aspect.

Older orthophotos of the same place, published in Norway through Norge i bilder. HOMAI compares historical and current imagery for its historical-change factor (default weight 0.10), a model-inferred signal of visible change over time. It does not date the roof: building age comes only from the official byggeår.

The angle of a roof plane against the horizontal. HOMAI's vision model reports pitch in degrees and as a class, and the value is cross-checked against LiDAR. Pitch is one of the 10 roof risk factors, with a default weight of 0.05. The share of the roof that is flat is scored as a separate factor, with a default weight of 0.08.

Anything that passes through the roof covering: chimneys, roof windows and vents. Each one breaks the covering and has to be sealed. HOMAI's vision model counts them quadrant by quadrant and prefers a slight under-count to an invented feature; uncertain counts are shown as ~N. Penetrations are a roof risk factor with a default weight of 0.10.

A digital model of a physical object, such as a building or a whole city, kept in step with data about the real thing. The 3D story on the CUATRO home page shows a 3D city model of Oslo with buildings, terrain and trees. HOMAI reports are analyses run on demand for an address; they are not a continuously updated digital twin.

The risk of damage or loss caused by weather and climate hazards, such as floods, landslides, heavy rain and storms. It is usually split into acute risk from single events and chronic risk from slow, long-term change. HOMAI assesses four physical hazards for each Norwegian address: precipitation, flood, landslide and storm.

Acute hazards are events, such as a flood, a landslide or a storm. Chronic hazards are gradual shifts, such as a wetter climate or rising sea levels, that raise exposure over years. HOMAI's climate score uses current hazard maps and ten years of observed weather statistics. It describes today's exposure and does not model future climate scenarios.

Financial risk that comes from the move to a low-carbon economy rather than from the weather: new regulation, technology and changing market expectations. Most climate-risk frameworks pair it with physical risk. HOMAI covers physical risk only. It does not assess transition risk, such as the effect of energy requirements on a building's value.

A flood zone (flomsone) is an area that NVE has mapped as flooded by a river flood of a given return period, for example a 200-year flood. HOMAI checks whether the building lies inside an NVE flood zone, and for which return period, as part of the flood exposure in the climate score.

The average time between events of at least a given size. A 200-year flood has a 1-in-200 (0.5 %) chance of happening in any single year, so it can occur twice in a decade. NVE maps flood zones for set return periods, and HOMAI uses the return period of the zone a building lies in when it bands the flood exposure.

NVE's flood susceptibility maps (aktsomhetsområder for flom) are coarser screening maps that show where flooding may be possible, including where no detailed flood zone map exists. They flag a need for closer assessment rather than a mapped flood level. HOMAI combines them with the flood zones when it bands the flood exposure of an address.

NVE's landslide susceptibility maps (aktsomhetskart for skred) are national screening maps of areas where landslides, rockfall, debris flows or snow avalanches may occur. Like the flood susceptibility maps, they show where closer assessment is needed. HOMAI checks the building's position against them for the landslide exposure in the climate score.

Quick clay (kvikkleire) is a marine clay that can lose its strength and turn almost liquid when disturbed, which can set off large, fast landslides. It occurs in parts of Norway that lay below the sea after the last ice age. HOMAI's landslide exposure is based on NVE's landslide susceptibility maps; it is not a geotechnical quick-clay assessment.

Rain or snow that is unusually intense over a short time, or unusually large over a day. HOMAI bands precipitation exposure from 1 to 5 using ten years of statistics from MET Norway's Frost service at the nearest weather station, including the largest daily total and the number of heavy-rain days.

A short, sudden peak in wind speed above the average wind. HOMAI bands storm exposure from 1 to 5 using ten years of gust statistics from the nearest weather station, taken from the Frost API of MET Norway (the Norwegian Meteorological Institute).

The weight of snow resting on a roof. Norwegian building standards give a characteristic ground snow load for each municipality, and roofs are designed for the load that follows from it. HOMAI does not score snow load: its climate score covers four hazards (precipitation, flood, landslide and storm). Roof shape and pitch appear in the report, but no snow-load calculation is made.

HOMAI's roof risk index, where a higher number means more risk. It is the weighted sum of the 10 roof risk factors, each scored from 0 to 100, plus a confidence drag and, when fewer than three factors could be scored, a coverage penalty. The health index is its mirror image: 100 minus the risk index. By default the roof index carries 40 % of the overall property score.

HOMAI's score from 0 to 10 for the climate exposure of an address. It combines four hazards, each banded from 1 to 5: precipitation and storm from MET Norway statistics, flood and landslide from NVE maps. By default it carries 60 % of the overall property score, and it is also one of the 10 roof risk factors.

A term in HOMAI's risk index that adds up to eight points when the inputs are uncertain, calculated as (1 − confidence) × 8. Low confidence therefore pushes the index towards higher risk instead of hiding the uncertainty, so a weakly evidenced roof does not get a lower score for it.

Ten points added to HOMAI's risk index when fewer than three roof risk factors could be scored. Factors that cannot be scored default to a neutral 50 with low confidence. The penalty keeps an analysis with thin coverage from producing a reassuringly low score.

A tag on every derived value in a HOMAI report that says how it was obtained: official, calculated, ai_estimated, ai_inferred or estimated. Each value also names its provider, a confidence between 0 and 1 and a short basis in plain words. Values that cannot be found are shown as not assessed rather than filled in.

A score produced by fixed rules, so the same inputs always give the same result. In HOMAI the AI describes the roof but never sets the score; plain arithmetic over weighted factors does. The same property, imagery and weights give the same score, and the report prints the formula with the property's own numbers filled in.

The EU's classification system for environmentally sustainable economic activities. To count as taxonomy-aligned, an activity must also do no significant harm to climate change adaptation, which for buildings means assessing the physical climate risks to the asset. HOMAI's building-level hazard data can feed that work, but HOMAI does not produce forward-looking climate scenarios.

An assessment of which physical climate hazards could affect an asset over its expected life and how vulnerable the asset is to them. Under the EU Taxonomy it is expected to draw on climate projections for future scenarios. HOMAI's current hazard data per building can be one input, but HOMAI does not run climate scenarios and is not a complete CRVA.

Norway's scheme for insuring against damage from natural events such as storm, flood, landslide and storm surge. The cover follows from fire insurance, and insurers share the claims through the Norwegian Natural Perils Pool (Norsk Naturskadepool). HOMAI is not part of the scheme; its hazard data describes the exposure of each address.

The Norwegian scale used in building condition reports (tilstandsrapport): TG0 means no deviation, TG1 minor or moderate deviation, TG2 significant deviation and TG3 major or serious deviation. Grades are set by a qualified surveyor on site. HOMAI does not issue condition grades; its remote roof assessment helps decide which buildings to inspect first.

A plan of a building's parts, their condition and the maintenance due in the coming years, used by housing associations (borettslag and sameier) and other owners to budget and prioritise. A HOMAI report includes a maintenance-plan section drafted from the roof findings and official data. It is an input to the plan, not a replacement for it.

A test of how a bank's or insurer's balance sheet would hold up under adverse climate scenarios, covering both physical and transition risk. Supervisors and central banks use such tests, and they depend on data about the assets behind the loans. HOMAI supplies building-level physical hazard data for Norwegian properties; it does not run stress tests or scenarios itself.